US6291084B1 - Nickel aluminide coating and coating systems formed therewith - Google Patents
Nickel aluminide coating and coating systems formed therewith Download PDFInfo
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- US6291084B1 US6291084B1 US09/608,114 US60811400A US6291084B1 US 6291084 B1 US6291084 B1 US 6291084B1 US 60811400 A US60811400 A US 60811400A US 6291084 B1 US6291084 B1 US 6291084B1
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- zirconium
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- chromium
- coating system
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- 238000000576 coating method Methods 0.000 title claims abstract description 93
- 239000011248 coating agent Substances 0.000 title claims abstract description 71
- NPXOKRUENSOPAO-UHFFFAOYSA-N Raney nickel Chemical compound [Al].[Ni] NPXOKRUENSOPAO-UHFFFAOYSA-N 0.000 title claims abstract description 40
- 229910000907 nickel aluminide Inorganic materials 0.000 title description 41
- 239000011651 chromium Substances 0.000 claims abstract description 60
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 54
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 53
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims abstract description 52
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 52
- 229910000943 NiAl Inorganic materials 0.000 claims abstract description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 28
- 239000000919 ceramic Substances 0.000 claims description 22
- 229910052782 aluminium Inorganic materials 0.000 claims description 16
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 15
- 229910052759 nickel Inorganic materials 0.000 claims description 14
- 239000000758 substrate Substances 0.000 claims description 13
- 229910000601 superalloy Inorganic materials 0.000 claims description 10
- 229910001233 yttria-stabilized zirconia Inorganic materials 0.000 claims description 6
- 239000012720 thermal barrier coating Substances 0.000 abstract description 46
- 230000007613 environmental effect Effects 0.000 abstract description 18
- 238000007792 addition Methods 0.000 abstract description 12
- 238000005275 alloying Methods 0.000 abstract description 5
- 239000010410 layer Substances 0.000 description 24
- 238000009792 diffusion process Methods 0.000 description 17
- 230000000694 effects Effects 0.000 description 13
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 12
- 239000007789 gas Substances 0.000 description 12
- 238000005328 electron beam physical vapour deposition Methods 0.000 description 10
- 239000000463 material Substances 0.000 description 10
- 230000003647 oxidation Effects 0.000 description 10
- 238000007254 oxidation reaction Methods 0.000 description 10
- 238000012360 testing method Methods 0.000 description 10
- 238000005260 corrosion Methods 0.000 description 9
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 8
- 230000007797 corrosion Effects 0.000 description 8
- 230000015572 biosynthetic process Effects 0.000 description 7
- 238000005240 physical vapour deposition Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 6
- 229910000951 Aluminide Inorganic materials 0.000 description 5
- 125000004122 cyclic group Chemical group 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 230000001681 protective effect Effects 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 238000000151 deposition Methods 0.000 description 4
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000011835 investigation Methods 0.000 description 3
- 230000035882 stress Effects 0.000 description 3
- 229910052715 tantalum Inorganic materials 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 230000001464 adherent effect Effects 0.000 description 2
- 229910010293 ceramic material Inorganic materials 0.000 description 2
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 2
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Chemical group 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical group [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 235000002639 sodium chloride Nutrition 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 2
- 238000007751 thermal spraying Methods 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 241000968352 Scandia <hydrozoan> Species 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000005137 deposition process Methods 0.000 description 1
- 238000013400 design of experiment Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000013213 extrapolation Methods 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 238000003055 full factorial design Methods 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- 239000001995 intermetallic alloy Substances 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- HJGMWXTVGKLUAQ-UHFFFAOYSA-N oxygen(2-);scandium(3+) Chemical compound [O-2].[O-2].[O-2].[Sc+3].[Sc+3] HJGMWXTVGKLUAQ-UHFFFAOYSA-N 0.000 description 1
- 238000007750 plasma spraying Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000009419 refurbishment Methods 0.000 description 1
- 229910001173 rene N5 Inorganic materials 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052702 rhenium Inorganic materials 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
- 238000005382 thermal cycling Methods 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
- C23C14/14—Metallic material, boron or silicon
- C23C14/16—Metallic material, boron or silicon on metallic substrates or on substrates of boron or silicon
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
- C23C28/021—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material including at least one metal alloy layer
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
- C23C28/321—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer with at least one metal alloy layer
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
- C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
- C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
- C23C28/3455—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
- Y10T428/12611—Oxide-containing component
- Y10T428/12618—Plural oxides
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12736—Al-base component
- Y10T428/1275—Next to Group VIII or IB metal-base component
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12771—Transition metal-base component
- Y10T428/12861—Group VIII or IB metal-base component
- Y10T428/12944—Ni-base component
Definitions
- This invention relates to coatings of the type used to protect components exposed to high temperature environments, such as the hostile thermal environment of a gas turbine engine. More particularly, this invention is directed to a predominantly beta ( ⁇ ) phase NiAl overlay coating that is alloyed to exhibit enhanced environmental properties, and as a result is useful as an environmental coating and as a bond coat for a thermal insulating ceramic layer.
- TBC thermal barrier coating
- Diffusion coatings such as diffusion aluminides and particularly platinum aluminides (PtAl), and overlay coatings, particularly MCrAlY alloys (where M is iron, cobalt and/or nickel), have been widely employed as environmental coatings for gas turbine engine components.
- Ceramic materials such as zirconia (ZrO 2 ) partially or fully stabilized by yttria (Y 2 O 3 ), magnesia (MgO) or other oxides, are widely used as a topcoat of TBC systems used on gas turbine engine components.
- the ceramic layer is typically deposited by air plasma spraying (APS) or a physical vapor deposition (PVD) technique.
- TBC employed in the highest temperature regions of gas turbine engines is typically deposited by electron beam physical vapor deposition (EBPVD) techniques which yield a columnar grain structure that is able to expand and contract without causing damaging stresses that lead to spallation.
- EBPVD electron beam physical vapor deposition
- thermal barrier coatings must have low thermal conductivity, strongly adhere to the article, and remain adherent throughout many heating and cooling cycles. The latter requirement is particularly demanding due to the different coefficients of thermal expansion between thermal barrier coating materials and superalloys typically used to form turbine engine components.
- Thermal barrier coating systems capable of satisfying the above requirements have generally required a bond coat, typically one or both of the above-noted diffusion aluminide and MCrAlY coatings.
- the aluminum content of a bond coat formed from these materials provides for the slow growth of a strong adherent continuous aluminum oxide layer (alumina scale) at elevated temperatures. This thermally grown oxide (TGO) protects the bond coat from oxidation and hot corrosion, and chemically bonds the ceramic layer to the bond coat.
- TGO thermally grown oxide
- bond coat materials are particularly alloyed to be oxidation-resistant, the surface oxidation and interdiffusion (with the substrate) that occurs over time at elevated temperatures gradually deplete aluminum from the bond coat. Eventually, the level of aluminum within the bond coat can become sufficiently depleted to prevent further slow growth of the protective alumina scale and to allow for the more rapid growth of nonprotective oxides, the result of which again is spallation of the ceramic layer.
- the ability of the bond coat to form the desired alumina scale can be hampered by the interdiffusion of certain elements between the superalloy and bond coat, such as during formation of a diffusion aluminide coating and during high temperature exposure.
- NiAl intermetallic alloys are reported in commonly-assigned U.S. Pat. Nos. 5,116,438, 5,116,691, 5,215,831 and 5,516,380 as suitable for forming load-bearing gas turbine engine components. These patents are primarily concerned with alloying the NiAl intermetallic to improve high temperature mechanical strength and low temperature ductility, neither of which is of particular concern for TBC bond coats, since bond coats are deposited as sacrificial layers on the outer surfaces of components and do not contribute to the strength of the components. NiAl intermetallic has also been proposed as an environmental coating in U.S. Pat. No.
- Darolia also teaches that minimizing the diffusion zone between a NiAl bond coat and its underlying substrate promotes the formation of an initial layer of essentially pure aluminum oxide, promotes the slow growth of the protective aluminum oxide layer during service, and reduces the formation of voluminous nonadherent oxides of substrate constituents that tend to diffuse into the bond coat, such as nickel, cobalt, chromium, titanium, tantalum, tungsten and molybdenum.
- NiAl bond coats can perform extremely well as a bond coat for a TBC if properly alloyed and deposited to contain only NiAl intermetallic and zirconium.
- the present invention generally provides a protective overlay coating for articles used in hostile thermal environments, such as turbine, combustor and augmentor components of a gas turbine engine.
- the method is particularly directed to increasing the environmental resistance of a predominantly beta-phase NiAl overlay coating for use as an environmental coating, as well as to improve the spallation resistance of a thermal barrier coating (TBC) deposited on the surface of such an overlay coating.
- TBC thermal barrier coating
- an unexpected improvement in spallation resistance and cyclic hot corrosion/oxidation (CHC/O) resistance is achieved with beta-phase NiAl overlay bond coats alloyed to contain certain amounts of chromium and zirconium, in combination, as compared to prior art beta-phase NiAl environmental coatings and TBC bond coats.
- the overlay coating of this invention contains 30 to 60 atomic percent aluminum so as to be predominantly of the beta-NiAl phase.
- the overlay coating also contains about 2 to 15 atomic percent chromium and about 0.1 to 1.2 atomic percent zirconium, which when present together in a beta-phase NiAl overlay bond coat, have been shown to improve the spallation resistance of a TBC deposited on the overlay bond coat.
- the maximum level at which zirconium produces a beneficial effect is significantly increased as compared to prior art NiAl+Zr overlay coatings.
- the NiAl overlay coating of this invention also exhibits sufficient CHC/O resistance to survive numerous cycles after spallation of the TBC has occurred. Accordingly, in addition to being suitable as a bond coat for a TBC system, the protective beta-phase NiAl overlay coating of this invention also has application as an environmental coating.
- FIG. 1 is a perspective view of a high pressure turbine blade.
- FIG. 2 is a cross-sectional view of the blade of FIG. 1 along line 2 — 2 , and shows a thermal barrier coating system on the blade in accordance with an embodiment of this invention.
- FIG. 3 is a graph illustrating the relative furnace cycle test spallation performance of NiAl intermetallic bond coats alloyed in accordance with this invention to contain 5 at. % chromium and 0.1 to 1.2 at. % zirconium.
- FIGS. 4 and 5 are main effects plots that evidence the effect of chromium and zirconium combinations on the TBC spallation resistance and the cyclic hot corrosion/oxidation (CHC/O) resistance of burner rig superalloy specimens having NiAl intermetallic overlay bond coats alloyed in accordance with this invention to contain 2 to 10 at. % chromium and 0.1 to 0.7 at. % zirconium.
- the present invention is generally applicable to components that operate within environments characterized by relatively high temperatures, and are therefore subjected to severe thermal stresses and thermal cycling.
- Notable examples of such components include the high and low pressure turbine nozzles and blades, shrouds, combustor liners and augmentor hardware of gas turbine engines.
- One such example is the high pressure turbine blade 10 shown in FIG. 1 .
- the blade 10 generally includes an airfoil 12 against which hot combustion gases are directed during operation of the gas turbine engine, and whose surface is therefore subjected to severe attack by oxidation, corrosion and erosion.
- the airfoil 12 is anchored to a turbine disk (not shown) with a dovetail 14 formed on a root section 16 of the blade 10 .
- Cooling holes 18 are present in the airfoil 12 through which bleed air is forced to transfer heat from the blade 10 . While the advantages of this invention will be described with reference to the high pressure turbine blade 10 shown in FIG. 1, and particularly nickel-base superalloy blades of the type shown in FIG. 1, the teachings of this invention are generally applicable to any component on which a coating system may be used to protect the component from its environment.
- the coating system 20 includes a ceramic layer 26 bonded to the blade substrate 22 with a NiAl overlay coating 24 , which therefor serves as a bond coat to the ceramic layer 26 .
- the substrate 22 (blade 10 ) is preferably a high-temperature material, such as an iron, nickel or cobalt-base superalloy.
- the ceramic layer 26 is preferably deposited by physical vapor deposition (PVD), though other deposition techniques could be used.
- a preferred material for the ceramic layer 26 is an yttria-stabilized zirconia (YSZ), with a suitable composition being about 3 to about 20 weight percent yttria, though other ceramic materials could be used, such as yttria, nonstabilized zirconia, or zirconia stabilized by ceria (CeO 2 ), scandia (Sc 2 O 3 ) or other oxides.
- the ceramic layer 26 is deposited to a thickness that is sufficient to provide the required thermal protection for the underlying substrate 22 and blade 10 , generally on the order of about 100 to about 300 micrometers.
- the surface of the overlay coating 24 oxidizes to form an oxide surface layer (scale) 28 to which the ceramic layer 26 chemically bonds.
- the NiAl overlay coating 24 is predominantly of the beta ( ⁇ ) NiAl phase with limited alloying additions.
- the NiAl overlay coating 24 is formed using a PVD process, preferably magnetron sputter physical vapor deposition or electron beam physical vapor deposition (EBPVD), though it is foreseeable that other deposition techniques could be used, such as thermal spraying of powders.
- an adequate thickness for the overlay coating 24 is about 15 micrometers in order to protect the underlying substrate 22 and provide an adequate supply of aluminum for oxide formation, though thicknesses of about 10 to about 125 micrometers are believed to be suitable.
- the above PVD techniques are preferably carried out to reduce the diffusion of the overlay coating 24 into the substrate 22 .
- deposition of the overlay coating 24 results in virtually no diffusion between the overlay coating 24 and substrate 22 .
- a very thin diffusion zone 30 of not more than about five micrometers, typically about 2.5 to 5 micrometers, may develop.
- a suitable heat treatment is two to four hours at about 1800° F. to 2000° F. (about 980° C. to about 1090° C.) in a vacuum or an inert atmosphere such as argon.
- the minimal thickness of the diffusion zone 30 promotes the initial formation of the scale 28 as essentially pure aluminum oxide (alumina), promotes the slow growth of the protective alumina scale 28 during service, reduces the formation of voluminous nonadherent oxides at the bond coat-ceramic layer interface, and reduces the amount of substrate material that must be removed during refurbishment of the TBC system 20 . Accordingly, articles such as the blade 10 shown in FIG. 1 can be refurbished more times than would be possible if a diffusion bond coat were used.
- the NiAl overlay coating 24 of this invention has an aluminum content of about 30 to 60 atomic percent, preferably about 30 to 50 atomic percent, and more preferably at an atomic ratio of 1:1 with nickel.
- the addition of about 2 to 15 atomic percent chromium and about 0.1 to 1.2 atomic percent zirconium to the predominantly beta-phase NiAl overlay coating 24 has a significant effect on the spallation resistance of the ceramic layer 26 adhered to the overlay coating 24 to form the TBC system 20 .
- chromium and zirconium have been shown to improve the spallation resistance of a ceramic layer deposited on the NiAl overlay coating the overlay coating 24 , and to improve the cyclic hot corrosion/oxidation (CHC/O) resistance of the overlay coating 24 when used alone as an environmental coating.
- CHC/O cyclic hot corrosion/oxidation
- the diffusion of chromium (which typically occurs in ranges of about 0.5 to 2 atomic percent) from superalloy substrates into prior art bond coats has been viewed as detrimental to TBC spallation resistance on the basis of encouraging the growth rate of aluminum oxide and nonadherent oxides at the bond coat-ceramic layer interface.
- the present invention intentionally alloys a beta-phase NiAl bond coat with chromium additions to levels higher than 2 atomic percent unexpectedly improve the spallation resistance of a TBC system.
- zirconium in the NiAl overlay coating 24 of this invention preferentially oxidizes at the coating surface, forming “pegs” that increase the mechanical integrity of the alumina scale 28 that forms on the coating 24 . These pegs create an irregular or roughened surface that increases the extrinsic resistance to crack propagation at the bond coat-TBC interface by providing a tortuous crack path. Zirconium is further believed to improve the creep resistance of the coating 24 .
- EBPVD techniques were used to deposit NiAl+Zr+Cr overlay coatings on six sets of furnace cycle test (FCT) buttons made from Rene N5 single-crystal superalloy, having a nominal composition, in weight percent, of 7.5% Co, 7.0% Cr, 6.5% Ta, 6.2% Al, 5.0% W, 3.0% Re, 1.5% Mo, 0.15% Hf, 0.05% C, 0.004% B, 0.01% Y, the balance nickel.
- FCT furnace cycle test
- the EBPVD parameters were adjusted to vary the zirconium content from one button set to another, while maintaining chromium levels of about 5 at. %.
- chromium levels of 2, 5 and 10 at. % and zirconium levels of 0.1, 0.3, 0.5, and 0.7 at. % were evaluated in a full factorial design of experiment (DOE).
- DOE full factorial design of experiment
- the ratio of aluminum to nickel atomic concentrations in the powders was maintained at about 1:1 for all powders investigated.
- the twelve possible combinations established by the chromium and zirconium ranges were formed as powders and sprayed by HVOF on test specimens.
- the TBC-coated pins were then subjected to burner rig testing for TBC spallation as overlay bond coats, while the TBC-free pins were subjected to burner rig testing with fuel contaminated with sea salt to evaluate the environmental properties of the NiAl+Zr+Cr compositions as environmental overlay coatings.
- the results of these tests are summarized in FIGS. 4 and 5, respectively.
- FIG. 4 is a “main effects” plot of zirconium and chromium chemistry concentration on TBC spallation life. A main effects plot was chosen as the simplest means to compare the average effects of separate variables on an outcome. In FIG.
- both zirconium and chromium have a clear effect on performance, as indicated by longer life with increasing concentrations of both elements, especially zirconium at levels between 0.3 to 0.7 at. %, and particular around 0.5 at. %.
- the effect of chromium is evident at all levels from 2 to 10 at. %.
- the main effects plot of FIG. 4 and the raw data that produced the plot indicated that the coatings with the longest lives contained a combination of 10 at. % chromium and 0.5 at. % zirconium. Coatings with more or less zirconium and less chromium did not perform as well.
- the plot also displays strong evidence by extrapolation that the lack of chromium (i.e., 0 at. % chromium) would lead to lower performance than the tested combinations of chromium and zirconium. Consequently, this investigation evidenced that the tested combinations of zirconium and chromium provide better spallation performance than if either element were used alone.
- zirconium concentrations of more than 0.7 at. % should perform better than baseline PtAl bond coats, as will chromium levels of more than 10 at. %. From this investigation, it was concluded that zirconium levels of about 0.1 to about 1.2 at. % and chromium levels of about 2 to about 15 at. % should be operable ranges to meet or exceed the performance of PtAl diffusion bond coats.
- FIG. 5 is a Main Effects plot of zirconium and chromium chemistry concentration on CHC/O life.
- the effects of the zirconium and chromium concentrations are similar to that seen in FIG. 4, in that both zirconium and chromium were required for full performance benefits to be realized.
- FIG. 5 further emphasizes the need to have both zirconium and chromium in the coating to achieve improved performance beyond what is possible with zirconium additions alone. Specifically, without chromium (0 at. %), the performance would be expected to be lower that the results obtained with a 2 at. % chromium level, no matter what the zirconium concentration (0.1 to 0.7 at. %) is of the coating.
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Abstract
An environmental overlay coating for articles used in hostile thermal environments, such as turbine, combustor and augmentor components of a gas turbine engine. The overlay coating is predominantly beta-phase NiAl with limited alloying additions of zirconium and chromium. The overlay coating is useful as an environmental coating and as a bond coat that improves the spallation resistance of a thermal barrier coating (TBC) system.
Description
This is a continuation-in-part patent application of U.S. patent application Ser. No. 09/166,883 filed Oct. 6, 1998 now U.S. Pat. No. 6,153,313.
This invention relates to coatings of the type used to protect components exposed to high temperature environments, such as the hostile thermal environment of a gas turbine engine. More particularly, this invention is directed to a predominantly beta (β) phase NiAl overlay coating that is alloyed to exhibit enhanced environmental properties, and as a result is useful as an environmental coating and as a bond coat for a thermal insulating ceramic layer.
Higher operating temperatures for gas turbine engines are continuously sought in order to increase their efficiency. However, as operating temperatures increase, the high temperature durability of the components within the engine must correspondingly increase. Significant advances in high temperature capabilities have been achieved through the formulation of nickel and cobalt-base superalloys. Nonetheless, when used to form components of the turbine, combustor and augmentor sections of a gas turbine engine, such alloys alone are often susceptible to damage by oxidation and hot corrosion attack and may not retain adequate mechanical properties. For this reason, these components are often protected by an environmental and/or thermal-insulating coating, the latter of which is termed a thermal barrier coating (TBC) system.
Diffusion coatings, such as diffusion aluminides and particularly platinum aluminides (PtAl), and overlay coatings, particularly MCrAlY alloys (where M is iron, cobalt and/or nickel), have been widely employed as environmental coatings for gas turbine engine components. Ceramic materials such as zirconia (ZrO2) partially or fully stabilized by yttria (Y2O3), magnesia (MgO) or other oxides, are widely used as a topcoat of TBC systems used on gas turbine engine components. The ceramic layer is typically deposited by air plasma spraying (APS) or a physical vapor deposition (PVD) technique. TBC employed in the highest temperature regions of gas turbine engines is typically deposited by electron beam physical vapor deposition (EBPVD) techniques which yield a columnar grain structure that is able to expand and contract without causing damaging stresses that lead to spallation.
To be effective, thermal barrier coatings must have low thermal conductivity, strongly adhere to the article, and remain adherent throughout many heating and cooling cycles. The latter requirement is particularly demanding due to the different coefficients of thermal expansion between thermal barrier coating materials and superalloys typically used to form turbine engine components. Thermal barrier coating systems capable of satisfying the above requirements have generally required a bond coat, typically one or both of the above-noted diffusion aluminide and MCrAlY coatings. The aluminum content of a bond coat formed from these materials provides for the slow growth of a strong adherent continuous aluminum oxide layer (alumina scale) at elevated temperatures. This thermally grown oxide (TGO) protects the bond coat from oxidation and hot corrosion, and chemically bonds the ceramic layer to the bond coat. However, a thermal expansion mismatch exists between the metallic bond coat, alumina scale and ceramic layer, and peeling stresses generated by this mismatch gradually increase over time to the point where spallation can occur at the interface between the bond coat and alumina scale or the interface between the alumina scale and ceramic layer.
Furthermore, though bond coat materials are particularly alloyed to be oxidation-resistant, the surface oxidation and interdiffusion (with the substrate) that occurs over time at elevated temperatures gradually deplete aluminum from the bond coat. Eventually, the level of aluminum within the bond coat can become sufficiently depleted to prevent further slow growth of the protective alumina scale and to allow for the more rapid growth of nonprotective oxides, the result of which again is spallation of the ceramic layer. In addition to depletion of aluminum, the ability of the bond coat to form the desired alumina scale can be hampered by the interdiffusion of certain elements between the superalloy and bond coat, such as during formation of a diffusion aluminide coating and during high temperature exposure.
From the above, it is apparent that the service life of a TBC system is dependent on the bond coat used to anchor the thermal insulating ceramic layer. Consequently, considerable research has been directed toward improved bond coats for TBC systems, including efforts directed to the use of oxidation-resistant materials other than diffusion aluminide coatings and MCrAlY overlay coatings. One example is bond coats formed of an overlay coating (i.e., not a diffusion) of beta (β) phase nickel aluminide (NiAl) intermetallic, whose composition is about 50 atomic percent (about 30 weight percent) aluminum, the balance being nickel. In the past, gas turbine engine components formed of NiAl intermetallic have been proposed. For example, advanced NiAl intermetallic alloys are reported in commonly-assigned U.S. Pat. Nos. 5,116,438, 5,116,691, 5,215,831 and 5,516,380 as suitable for forming load-bearing gas turbine engine components. These patents are primarily concerned with alloying the NiAl intermetallic to improve high temperature mechanical strength and low temperature ductility, neither of which is of particular concern for TBC bond coats, since bond coats are deposited as sacrificial layers on the outer surfaces of components and do not contribute to the strength of the components. NiAl intermetallic has also been proposed as an environmental coating in U.S. Pat. No. 4,610,736 to Barrett et al., in which additions of about 0.05 to 0.25 weight percent zirconium were shown to improve the cyclic oxidation resistance of the intermetallic, though whether such a coating could be used as a bond coat for a TBC system was not reported or evident.
More recently, in commonly-assigned U.S. patent application Ser. No. 09/232,518, filed Jan. 19, 1999, to Darolia, a beta-phase nickel aluminide bond coat containing 0.2 up to about 0.5 atomic percent zirconium is reported to promote the adhesion of a ceramic TBC layer to the extent that the service life of the resulting TBC system is drastically increased. Darolia also teaches that minimizing the diffusion zone between a NiAl bond coat and its underlying substrate promotes the formation of an initial layer of essentially pure aluminum oxide, promotes the slow growth of the protective aluminum oxide layer during service, and reduces the formation of voluminous nonadherent oxides of substrate constituents that tend to diffuse into the bond coat, such as nickel, cobalt, chromium, titanium, tantalum, tungsten and molybdenum. As such, Darolia teaches that NiAl bond coats can perform extremely well as a bond coat for a TBC if properly alloyed and deposited to contain only NiAl intermetallic and zirconium. Notably, Darolia subscribes to the conventional wisdom that alloying additions of chromium, titanium and tantalum to a bond coat detrimentally encourage the growth of alumina scale, leading to reduced spallation life of a ceramic layer on the bond coat. Consequently, it is apparent that the alloying requirements of NiAl intermetallic intended as an environmental coating or TBC bond coat differ from that of NiAl intermetallic used to form load-bearing articles, such as those of previously-mentioned U.S. Pat. No. 5,516,380.
Even with the advancements of Darolia, there remains a considerable and continuous effort to further increase the service life of TBC systems by improving the spallation resistance of the thermal insulating layer.
The present invention generally provides a protective overlay coating for articles used in hostile thermal environments, such as turbine, combustor and augmentor components of a gas turbine engine. The method is particularly directed to increasing the environmental resistance of a predominantly beta-phase NiAl overlay coating for use as an environmental coating, as well as to improve the spallation resistance of a thermal barrier coating (TBC) deposited on the surface of such an overlay coating. According to the invention, an unexpected improvement in spallation resistance and cyclic hot corrosion/oxidation (CHC/O) resistance is achieved with beta-phase NiAl overlay bond coats alloyed to contain certain amounts of chromium and zirconium, in combination, as compared to prior art beta-phase NiAl environmental coatings and TBC bond coats.
As a beta-phase NiAl intermetallic, the overlay coating of this invention contains 30 to 60 atomic percent aluminum so as to be predominantly of the beta-NiAl phase. As a key feature of this invention, the overlay coating also contains about 2 to 15 atomic percent chromium and about 0.1 to 1.2 atomic percent zirconium, which when present together in a beta-phase NiAl overlay bond coat, have been shown to improve the spallation resistance of a TBC deposited on the overlay bond coat. In the presence of chromium, the maximum level at which zirconium produces a beneficial effect is significantly increased as compared to prior art NiAl+Zr overlay coatings. Also of particular note is that the inclusion of limited amounts of chromium unexpectedly has a very substantial effect on spallation resistance, contrary to conventional wisdom that significant additions of chromium to beta-phase NiAl detrimentally encourages the growth of alumina scale and reduce spallation life. The net effect of the amounts of chromium and zirconium proposed by this invention is a significant improvement in cyclic hot corrosion and oxidation (CHC/O) performance of the overlay coating of this invention, and an increase in the life of a TBC on the overlay coating.
Notably, the NiAl overlay coating of this invention also exhibits sufficient CHC/O resistance to survive numerous cycles after spallation of the TBC has occurred. Accordingly, in addition to being suitable as a bond coat for a TBC system, the protective beta-phase NiAl overlay coating of this invention also has application as an environmental coating.
Other objects and advantages of this invention will be better appreciated from the following detailed description.
FIG. 1 is a perspective view of a high pressure turbine blade.
FIG. 2 is a cross-sectional view of the blade of FIG. 1 along line 2—2, and shows a thermal barrier coating system on the blade in accordance with an embodiment of this invention.
FIG. 3 is a graph illustrating the relative furnace cycle test spallation performance of NiAl intermetallic bond coats alloyed in accordance with this invention to contain 5 at. % chromium and 0.1 to 1.2 at. % zirconium.
FIGS. 4 and 5 are main effects plots that evidence the effect of chromium and zirconium combinations on the TBC spallation resistance and the cyclic hot corrosion/oxidation (CHC/O) resistance of burner rig superalloy specimens having NiAl intermetallic overlay bond coats alloyed in accordance with this invention to contain 2 to 10 at. % chromium and 0.1 to 0.7 at. % zirconium.
The present invention is generally applicable to components that operate within environments characterized by relatively high temperatures, and are therefore subjected to severe thermal stresses and thermal cycling. Notable examples of such components include the high and low pressure turbine nozzles and blades, shrouds, combustor liners and augmentor hardware of gas turbine engines. One such example is the high pressure turbine blade 10 shown in FIG. 1. The blade 10 generally includes an airfoil 12 against which hot combustion gases are directed during operation of the gas turbine engine, and whose surface is therefore subjected to severe attack by oxidation, corrosion and erosion. The airfoil 12 is anchored to a turbine disk (not shown) with a dovetail 14 formed on a root section 16 of the blade 10. Cooling holes 18 are present in the airfoil 12 through which bleed air is forced to transfer heat from the blade 10. While the advantages of this invention will be described with reference to the high pressure turbine blade 10 shown in FIG. 1, and particularly nickel-base superalloy blades of the type shown in FIG. 1, the teachings of this invention are generally applicable to any component on which a coating system may be used to protect the component from its environment.
Represented in FIG. 2 is a TBC system 20 of a type that benefits from the teachings of this invention. As shown, the coating system 20 includes a ceramic layer 26 bonded to the blade substrate 22 with a NiAl overlay coating 24, which therefor serves as a bond coat to the ceramic layer 26. The substrate 22 (blade 10) is preferably a high-temperature material, such as an iron, nickel or cobalt-base superalloy. To attain a strain-tolerant columnar grain structure, the ceramic layer 26 is preferably deposited by physical vapor deposition (PVD), though other deposition techniques could be used. A preferred material for the ceramic layer 26 is an yttria-stabilized zirconia (YSZ), with a suitable composition being about 3 to about 20 weight percent yttria, though other ceramic materials could be used, such as yttria, nonstabilized zirconia, or zirconia stabilized by ceria (CeO2), scandia (Sc2O3) or other oxides. The ceramic layer 26 is deposited to a thickness that is sufficient to provide the required thermal protection for the underlying substrate 22 and blade 10, generally on the order of about 100 to about 300 micrometers. As with prior art TBC systems, the surface of the overlay coating 24 oxidizes to form an oxide surface layer (scale) 28 to which the ceramic layer 26 chemically bonds.
According to the invention, the NiAl overlay coating 24 is predominantly of the beta (β) NiAl phase with limited alloying additions. The NiAl overlay coating 24 is formed using a PVD process, preferably magnetron sputter physical vapor deposition or electron beam physical vapor deposition (EBPVD), though it is foreseeable that other deposition techniques could be used, such as thermal spraying of powders. According to the invention, an adequate thickness for the overlay coating 24 is about 15 micrometers in order to protect the underlying substrate 22 and provide an adequate supply of aluminum for oxide formation, though thicknesses of about 10 to about 125 micrometers are believed to be suitable. The above PVD techniques are preferably carried out to reduce the diffusion of the overlay coating 24 into the substrate 22. Preferably, deposition of the overlay coating 24 results in virtually no diffusion between the overlay coating 24 and substrate 22. During subsequent heat treatment to relieve residual stresses generated during the deposition process, a very thin diffusion zone 30 of not more than about five micrometers, typically about 2.5 to 5 micrometers, may develop. A suitable heat treatment is two to four hours at about 1800° F. to 2000° F. (about 980° C. to about 1090° C.) in a vacuum or an inert atmosphere such as argon. Importantly, the minimal thickness of the diffusion zone 30 promotes the initial formation of the scale 28 as essentially pure aluminum oxide (alumina), promotes the slow growth of the protective alumina scale 28 during service, reduces the formation of voluminous nonadherent oxides at the bond coat-ceramic layer interface, and reduces the amount of substrate material that must be removed during refurbishment of the TBC system 20. Accordingly, articles such as the blade 10 shown in FIG. 1 can be refurbished more times than would be possible if a diffusion bond coat were used.
To attain the beta-NiAl intermetallic phase, the NiAl overlay coating 24 of this invention has an aluminum content of about 30 to 60 atomic percent, preferably about 30 to 50 atomic percent, and more preferably at an atomic ratio of 1:1 with nickel. According to this invention, the addition of about 2 to 15 atomic percent chromium and about 0.1 to 1.2 atomic percent zirconium to the predominantly beta-phase NiAl overlay coating 24 has a significant effect on the spallation resistance of the ceramic layer 26 adhered to the overlay coating 24 to form the TBC system 20.
According to the invention, additions of chromium and zirconium have been shown to improve the spallation resistance of a ceramic layer deposited on the NiAl overlay coating the overlay coating 24, and to improve the cyclic hot corrosion/oxidation (CHC/O) resistance of the overlay coating 24 when used alone as an environmental coating. These benefits have been shown to be the result of solid solution strengthening by chromium, and precipitation strengthening from fine α-Cr phases or β′ Heusler phases (in combination with additions of zirconium) dispersed within the beta phase of the bond coat. The result is believed to be a sufficient increase in the strength of the bond coat to limit the creep deformation and rumpling of the bond coat surface, which this invention has determined to contribute to early failures of conventional bond coat materials. Chromium additions are also believed to help in the formation of alpha alumina and improve the corrosion resistance of the bond coat.
Notably, the diffusion of chromium (which typically occurs in ranges of about 0.5 to 2 atomic percent) from superalloy substrates into prior art bond coats has been viewed as detrimental to TBC spallation resistance on the basis of encouraging the growth rate of aluminum oxide and nonadherent oxides at the bond coat-ceramic layer interface. Nonetheless, the present invention intentionally alloys a beta-phase NiAl bond coat with chromium additions to levels higher than 2 atomic percent unexpectedly improve the spallation resistance of a TBC system.
According to this invention, zirconium in the NiAl overlay coating 24 of this invention preferentially oxidizes at the coating surface, forming “pegs” that increase the mechanical integrity of the alumina scale 28 that forms on the coating 24. These pegs create an irregular or roughened surface that increases the extrinsic resistance to crack propagation at the bond coat-TBC interface by providing a tortuous crack path. Zirconium is further believed to improve the creep resistance of the coating 24.
During an investigation leading to this invention, tests were performed on NiAl+Zr+Cr overlay coatings 24 that evidenced improvements over baseline PtAl diffusion coatings in terms of TBC spallation and environmental (CHC/O) resistance. The tests showed that such improvements can be achieved with up to 1.2 at. % zirconium, and that the further addition of chromium leads to an unexpected additional improvement in TBC spallation and CHC/O performance. Suitable compositional ranges for zirconium and chromium were established through the testing of overlay coatings deposited by electron beam-physical vapor deposition (EB-PVD) and high velocity oxyfuel (HVOF) thermal spraying of powders.
In a first experiment, EBPVD techniques were used to deposit NiAl+Zr+Cr overlay coatings on six sets of furnace cycle test (FCT) buttons made from Rene N5 single-crystal superalloy, having a nominal composition, in weight percent, of 7.5% Co, 7.0% Cr, 6.5% Ta, 6.2% Al, 5.0% W, 3.0% Re, 1.5% Mo, 0.15% Hf, 0.05% C, 0.004% B, 0.01% Y, the balance nickel. The EBPVD parameters were adjusted to vary the zirconium content from one button set to another, while maintaining chromium levels of about 5 at. %. After depositing approximately two mils (about 50 micrometers) of NiAl+Zr+Cr overlay coating material, the specimens were subjected to a vacuum diffusion heat treatment at about 2000° F. (about 1090° C.) for two hours, and then coated by EBPVD with about five mils (about 125 micrometers) of 7% YSZ as a thermal barrier coating (TBC) material. The spallation life potentials of these coating systems were then evaluated by FCT at about 2125° F. (about 1160° C.) with one hour cycles. The results of this experiment are plotted in FIG. 3. The spallation resistance of the YSZ TBC is shown to be strongly influenced by zirconium concentration. FCT lives exceeding the PtAl baseline performance (230 cycles) were observed for zirconium levels of about 0.2 to 1.2 at. % zirconium, and particularly for levels of about 0.3 to about 0.7 at. %.
In a second experiment designed to evaluate the role of chromium and zirconium chemistry variations on the environmental performance of beta-phase NiAl overlay coatings, chromium levels of 2, 5 and 10 at. % and zirconium levels of 0.1, 0.3, 0.5, and 0.7 at. % were evaluated in a full factorial design of experiment (DOE). The ratio of aluminum to nickel atomic concentrations in the powders was maintained at about 1:1 for all powders investigated. The twelve possible combinations established by the chromium and zirconium ranges were formed as powders and sprayed by HVOF on test specimens. Coatings two mils (about 50 micrometers) in thickness were applied to René N5 pin specimens (3.5 inches long and 0.25 inches diameter; about 9 cm long by about 6.35 mm diameter). After a vacuum diffusion heat treatment at about 1975° F. (about 1080° C.) for two hours, the NiAl overlay coatings were hand-finished to reduce surface roughness. Half of the pins were then coated with about five mils (about 125 micrometers) of 7% YSZ by EBPVD. The TBC-coated pins were then subjected to burner rig testing for TBC spallation as overlay bond coats, while the TBC-free pins were subjected to burner rig testing with fuel contaminated with sea salt to evaluate the environmental properties of the NiAl+Zr+Cr compositions as environmental overlay coatings. The results of these tests are summarized in FIGS. 4 and 5, respectively.
The burner rig TBC spallation experiment with the TBC-coated specimens was conducted at Mach 0.5 gas velocity and at pin temperatures cycled between about 200° F. and 2075° F. (about 93° C. and about 1135° C.) using cycles comprised of a five minute hold at peak temperature and 75 seconds of forced air cooling to below 200° F. (about 93° C.). The number of cycles to TBC failure (identified as the spallation of any amount of TBC) was recorded. FIG. 4 is a “main effects” plot of zirconium and chromium chemistry concentration on TBC spallation life. A main effects plot was chosen as the simplest means to compare the average effects of separate variables on an outcome. In FIG. 4, for instance, the average performance for specimens containing about 10 at. % chromium (at all zirconium levels) was considerably higher than those with only 2 at. % chromium (at all zirconium levels). Similarly, coatings with 0.5 at. % zirconium (at all chromium levels) performed better than coatings with 0.1, 0.3 and 0.7 at. % zirconium (at all chromium levels).
As is evident from FIG. 4, both zirconium and chromium have a clear effect on performance, as indicated by longer life with increasing concentrations of both elements, especially zirconium at levels between 0.3 to 0.7 at. %, and particular around 0.5 at. %. The effect of chromium is evident at all levels from 2 to 10 at. %. The main effects plot of FIG. 4 and the raw data that produced the plot indicated that the coatings with the longest lives contained a combination of 10 at. % chromium and 0.5 at. % zirconium. Coatings with more or less zirconium and less chromium did not perform as well. The plot also displays strong evidence by extrapolation that the lack of chromium (i.e., 0 at. % chromium) would lead to lower performance than the tested combinations of chromium and zirconium. Consequently, this investigation evidenced that the tested combinations of zirconium and chromium provide better spallation performance than if either element were used alone.
The data also indicates the trend that zirconium concentrations of more than 0.7 at. % should perform better than baseline PtAl bond coats, as will chromium levels of more than 10 at. %. From this investigation, it was concluded that zirconium levels of about 0.1 to about 1.2 at. % and chromium levels of about 2 to about 15 at. % should be operable ranges to meet or exceed the performance of PtAl diffusion bond coats.
Finally, a burner rig CHC/O test was conducted with the twelve TBC-free NiAl+Zr+Cr overlay coatings deposited by HVOF. These specimens were subjected to a Mach 0.5 flame and a continuous thermal cycle between about 2075° F. (about 1135° C.) for five minutes and about 1700° F. (about 925° C.) for ten minutes, all while injecting 1 ppm sea salt into the fuel to achieve hot-corrosion. The time in hours required for the coating to be removed by environmental attack at any location was recorded. Subsequent metallographic analysis revealed the initial thickness of the coating, from which the life per mil (per about 25 micrometers) of coating was calculated. FIG. 5 is a Main Effects plot of zirconium and chromium chemistry concentration on CHC/O life. The effects of the zirconium and chromium concentrations are similar to that seen in FIG. 4, in that both zirconium and chromium were required for full performance benefits to be realized. FIG. 5 further emphasizes the need to have both zirconium and chromium in the coating to achieve improved performance beyond what is possible with zirconium additions alone. Specifically, without chromium (0 at. %), the performance would be expected to be lower that the results obtained with a 2 at. % chromium level, no matter what the zirconium concentration (0.1 to 0.7 at. %) is of the coating.
While the invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. Accordingly, the scope of the invention is to be limited only by the following claims.
Claims (16)
1. A coating system on a superalloy substrate, the coating system comprising a beta-phase NiAl intermetallic overlay layer consisting of, in atomic percent, 30% to 60% aluminum, 2% to 15% chromium, 0.1% to 1.2% zirconium, and the balance essentially nickel.
2. A coating system according to claim 1, further comprising a thermal-insulating ceramic layer adhered to the overlay layer.
3. A coating system according to claim 1, wherein the zirconium content of the overlay layer is 0.3 to 0.7 atomic percent.
4. A coating system according to claim 1, wherein the zirconium content of the overlay layer is about 0.5 atomic percent.
5. A coating system according to claim 1, wherein the chromium content of the overlay layer is 2 to 10 atomic percent.
6. A coating system according to claim 1, wherein the chromium content of the overlay layer is at least 5 atomic percent.
7. A coating system according to claim 1, wherein nickel and aluminum are present in the overlay layer in approximately equal amounts.
8. A coating system on a superalloy substrate, the coating system comprising a ceramic layer on a beta-phase NiAl intermetallic overlay bond coat, the overlay bond coat consisting of, in atomic percent, 30% to 50% aluminum, 2% to 15% chromium, 0.1% to 1.2% zirconium, and the balance essentially nickel.
9. A coating system according to claim 8, wherein the zirconium content of the overlay bond coat is 0.3 to 0.7 atomic percent.
10. A coating system according to claim 8, wherein the zirconium content of the overlay bond coat is about 0.5 atomic percent.
11. A coating system according to claim 8, wherein the chromium content of the overlay bond coat is 2 to 10 atomic percent.
12. A coating system according to claim 8, wherein the chromium content of the overlay bond coat is at least 5 atomic percent.
13. A coating system according to claim 8, wherein the overlay bond coat consists of, in atomic percent, 2% to 10% chromium, 0.2% to 1.2% zirconium, the balance essentially nickel and aluminum in approximately equal amounts.
14. A coating system according to claim 8, wherein the overlay bond coat consists of, in atomic percent, 5% to 10% chromium, 0.3% to 0.7% zirconium, the balance essentially nickel and aluminum in approximately equal amounts.
15. A coating system according to claim 8, wherein nickel and aluminum are present in the overlay bond coat in approximately equal amounts.
16. A coating system according to claim 8, wherein the ceramic layer is yttria-stabilized zirconia.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/608,114 US6291084B1 (en) | 1998-10-06 | 2000-06-30 | Nickel aluminide coating and coating systems formed therewith |
EP01305594A EP1167575A3 (en) | 2000-06-30 | 2001-06-27 | Nickel aluminide coating and coating systems formed therewith |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/166,883 US6153313A (en) | 1998-10-06 | 1998-10-06 | Nickel aluminide coating and coating systems formed therewith |
US09/608,114 US6291084B1 (en) | 1998-10-06 | 2000-06-30 | Nickel aluminide coating and coating systems formed therewith |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US09/166,883 Continuation-In-Part US6153313A (en) | 1998-10-06 | 1998-10-06 | Nickel aluminide coating and coating systems formed therewith |
Publications (1)
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US6291084B1 true US6291084B1 (en) | 2001-09-18 |
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US09/608,114 Expired - Fee Related US6291084B1 (en) | 1998-10-06 | 2000-06-30 | Nickel aluminide coating and coating systems formed therewith |
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US (1) | US6291084B1 (en) |
EP (1) | EP1167575A3 (en) |
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Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4530885A (en) | 1979-07-25 | 1985-07-23 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Nickel or cobalt alloy composite |
US4610736A (en) * | 1983-03-23 | 1986-09-09 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Nickel base coating alloy |
US4612165A (en) | 1983-12-21 | 1986-09-16 | The United States Of America As Represented By The United States Department Of Energy | Ductile aluminide alloys for high temperature applications |
US4731221A (en) | 1985-05-06 | 1988-03-15 | The United States Of America As Represented By The United States Department Of Energy | Nickel aluminides and nickel-iron aluminides for use in oxidizing environments |
US4916022A (en) | 1988-11-03 | 1990-04-10 | Allied-Signal Inc. | Titania doped ceramic thermal barrier coatings |
USRE33876E (en) | 1975-09-11 | 1992-04-07 | United Technologies Corporation | Thermal barrier coating for nickel and cobalt base super alloys |
US5108700A (en) | 1989-08-21 | 1992-04-28 | Martin Marietta Energy Systems, Inc. | Castable nickel aluminide alloys for structural applications |
US5116691A (en) * | 1991-03-04 | 1992-05-26 | General Electric Company | Ductility microalloyed NiAl intermetallic compounds |
US5116438A (en) | 1991-03-04 | 1992-05-26 | General Electric Company | Ductility NiAl intermetallic compounds microalloyed with gallium |
US5215831A (en) | 1991-03-04 | 1993-06-01 | General Electric Company | Ductility ni-al intermetallic compounds microalloyed with iron |
US5238752A (en) | 1990-05-07 | 1993-08-24 | General Electric Company | Thermal barrier coating system with intermetallic overlay bond coat |
US5302465A (en) | 1992-10-26 | 1994-04-12 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Plasma sprayed ceramic thermal barrier coating for NiAl-based intermetallic alloys |
US5427866A (en) | 1994-03-28 | 1995-06-27 | General Electric Company | Platinum, rhodium, or palladium protective coatings in thermal barrier coating systems |
US5516380A (en) | 1994-10-14 | 1996-05-14 | General Electric Company | NiAl intermetallic alloy and article with improved high temperature strength |
WO1997029219A2 (en) | 1996-02-07 | 1997-08-14 | N.V. Interturbine | Improved thermal barrier coating system and methods |
US5975852A (en) * | 1997-03-31 | 1999-11-02 | General Electric Company | Thermal barrier coating system and method therefor |
US6168874B1 (en) * | 1998-02-02 | 2001-01-02 | General Electric Company | Diffusion aluminide bond coat for a thermal barrier coating system and method therefor |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100354411B1 (en) * | 1994-10-14 | 2002-11-18 | 지멘스 악티엔게젤샤프트 | Protective layer for protecting parts against corrosion, oxidation and excessive thermal stresses, as well as process for producing the same |
US6153313A (en) * | 1998-10-06 | 2000-11-28 | General Electric Company | Nickel aluminide coating and coating systems formed therewith |
-
2000
- 2000-06-30 US US09/608,114 patent/US6291084B1/en not_active Expired - Fee Related
-
2001
- 2001-06-27 EP EP01305594A patent/EP1167575A3/en not_active Withdrawn
Patent Citations (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
USRE33876E (en) | 1975-09-11 | 1992-04-07 | United Technologies Corporation | Thermal barrier coating for nickel and cobalt base super alloys |
US4530885A (en) | 1979-07-25 | 1985-07-23 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Nickel or cobalt alloy composite |
US4610736A (en) * | 1983-03-23 | 1986-09-09 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Nickel base coating alloy |
US4612165A (en) | 1983-12-21 | 1986-09-16 | The United States Of America As Represented By The United States Department Of Energy | Ductile aluminide alloys for high temperature applications |
US4612165B1 (en) | 1983-12-21 | 1991-07-23 | Us Energy | |
US4731221A (en) | 1985-05-06 | 1988-03-15 | The United States Of America As Represented By The United States Department Of Energy | Nickel aluminides and nickel-iron aluminides for use in oxidizing environments |
US4916022A (en) | 1988-11-03 | 1990-04-10 | Allied-Signal Inc. | Titania doped ceramic thermal barrier coatings |
US5108700A (en) | 1989-08-21 | 1992-04-28 | Martin Marietta Energy Systems, Inc. | Castable nickel aluminide alloys for structural applications |
US5238752A (en) | 1990-05-07 | 1993-08-24 | General Electric Company | Thermal barrier coating system with intermetallic overlay bond coat |
US5116691A (en) * | 1991-03-04 | 1992-05-26 | General Electric Company | Ductility microalloyed NiAl intermetallic compounds |
US5215831A (en) | 1991-03-04 | 1993-06-01 | General Electric Company | Ductility ni-al intermetallic compounds microalloyed with iron |
US5116438A (en) | 1991-03-04 | 1992-05-26 | General Electric Company | Ductility NiAl intermetallic compounds microalloyed with gallium |
US5302465A (en) | 1992-10-26 | 1994-04-12 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Plasma sprayed ceramic thermal barrier coating for NiAl-based intermetallic alloys |
US5427866A (en) | 1994-03-28 | 1995-06-27 | General Electric Company | Platinum, rhodium, or palladium protective coatings in thermal barrier coating systems |
US5516380A (en) | 1994-10-14 | 1996-05-14 | General Electric Company | NiAl intermetallic alloy and article with improved high temperature strength |
WO1997029219A2 (en) | 1996-02-07 | 1997-08-14 | N.V. Interturbine | Improved thermal barrier coating system and methods |
US5824423A (en) | 1996-02-07 | 1998-10-20 | N.V. Interturbine | Thermal barrier coating system and methods |
US5975852A (en) * | 1997-03-31 | 1999-11-02 | General Electric Company | Thermal barrier coating system and method therefor |
US6168874B1 (en) * | 1998-02-02 | 2001-01-02 | General Electric Company | Diffusion aluminide bond coat for a thermal barrier coating system and method therefor |
Non-Patent Citations (2)
Title |
---|
Pint et al., Evaluation of TBC-Coated-NiA1 Substrates Without a Bond Coat, Elevated Temperature Coatings: Science and Tech. II, The Minerals, Metals and Materials Society, (1996), pp.163-173. |
Pint et al., Substrate and Bond Coat Compositions: Factors Affecting Alumina Scale Adhesion, NIST TBC Workshop 1997, Cincinnati OH (May 19-21, 1997), pp. 109-125. |
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US20070093811A1 (en) * | 2005-05-12 | 2007-04-26 | Orion Industries, Ltd. | Electrosurgical electrode and method of manufacturing same |
US20060259033A1 (en) * | 2005-05-12 | 2006-11-16 | Bruce Nesbitt | Electrosurgical electrode and method of manufacturing same |
US11246645B2 (en) | 2005-05-12 | 2022-02-15 | Innovatech, Llc | Electrosurgical electrode and method of manufacturing same |
US10463420B2 (en) | 2005-05-12 | 2019-11-05 | Innovatech Llc | Electrosurgical electrode and method of manufacturing same |
US9630206B2 (en) | 2005-05-12 | 2017-04-25 | Innovatech, Llc | Electrosurgical electrode and method of manufacturing same |
US8814861B2 (en) | 2005-05-12 | 2014-08-26 | Innovatech, Llc | Electrosurgical electrode and method of manufacturing same |
US8814863B2 (en) | 2005-05-12 | 2014-08-26 | Innovatech, Llc | Electrosurgical electrode and method of manufacturing same |
US8814862B2 (en) | 2005-05-12 | 2014-08-26 | Innovatech, Llc | Electrosurgical electrode and method of manufacturing same |
US7147634B2 (en) | 2005-05-12 | 2006-12-12 | Orion Industries, Ltd. | Electrosurgical electrode and method of manufacturing same |
US20060259032A1 (en) * | 2005-05-12 | 2006-11-16 | Bruce Nesbitt | Electrosurgical electrode and method of manufacturing same |
US7413778B2 (en) | 2005-12-05 | 2008-08-19 | General Electric Company | Bond coat with low deposited aluminum level and method therefore |
US20070128360A1 (en) * | 2005-12-05 | 2007-06-07 | General Electric Company | Bond coat with low deposited aluminum level and method therefore |
US20070160775A1 (en) * | 2006-01-10 | 2007-07-12 | General Electric Company | Physical vapor deposition process and apparatus therefor |
US20070207339A1 (en) * | 2006-03-06 | 2007-09-06 | Zimmerman Robert G Jr | Bond coat process for thermal barrier coating |
EP1927673A2 (en) | 2006-11-30 | 2008-06-04 | General Electric Company | NI-base superalloy having a coating system containing a stabilizing layer |
EP1939318A2 (en) | 2006-12-27 | 2008-07-02 | General Electric Company | Carburization process for stabilizing nickel-based superalloys |
US20080253923A1 (en) * | 2007-04-10 | 2008-10-16 | Siemens Power Generation, Inc. | Superalloy forming highly adherent chromia surface layer |
US20080260571A1 (en) * | 2007-04-19 | 2008-10-23 | Siemens Power Generation, Inc. | Oxidation resistant superalloy |
US20100136240A1 (en) * | 2007-05-07 | 2010-06-03 | O'connell Matthew James | Process for Forming an Outward Grown Aluminide Coating |
US8920937B2 (en) | 2007-08-05 | 2014-12-30 | United Technologies Corporation | Zirconium modified protective coating |
US20090035601A1 (en) * | 2007-08-05 | 2009-02-05 | Litton David A | Zirconium modified protective coating |
US8293378B2 (en) * | 2007-12-04 | 2012-10-23 | United States Pipe And Foundry Company Llc | Anti-corrosive coating for metal surfaces |
US20090252986A1 (en) * | 2007-12-04 | 2009-10-08 | United States Pipe And Foundry Co., Llc | Anti-corrosive coating for metal surfaces |
US20090162209A1 (en) * | 2007-12-19 | 2009-06-25 | David John Wortman | Turbine engine components with environmental protection for interior passages |
US8545185B2 (en) | 2007-12-19 | 2013-10-01 | General Electric Company | Turbine engine components with environmental protection for interior passages |
US20090162670A1 (en) * | 2007-12-20 | 2009-06-25 | General Electric Company | Method for applying ceramic coatings to smooth surfaces by air plasma spray techniques, and related articles |
US20090191422A1 (en) * | 2008-01-30 | 2009-07-30 | United Technologies Corporation | Cathodic ARC deposition coatings for turbine engine components |
WO2011084573A1 (en) | 2009-12-21 | 2011-07-14 | General Electric Company | Methods of forming nickel aluminide coatings |
US8697251B2 (en) | 2010-01-20 | 2014-04-15 | United States Pipe And Foundry Company, Llc | Protective coating for metal surfaces |
US20110177358A1 (en) * | 2010-01-20 | 2011-07-21 | United States Pipe And Foundry Company, Llc | Protective coating for metal surfaces |
WO2014169222A3 (en) * | 2013-04-12 | 2015-01-22 | University Of Virginia Patent Foundation | Corrosion resistant metal and metal alloy coatings containing supersaturated concentrations of corrosion inhibiting elements and methods and systems for making the same |
WO2014169222A2 (en) * | 2013-04-12 | 2014-10-16 | University Of Virginia Patent Foundation | Corrosion resistant metal and metal alloy coatings containing supersaturated concentrations of corrosion inhibiting elements and methods and systems for making the same |
US10767246B2 (en) | 2014-08-18 | 2020-09-08 | General Electric Company | Enhanced superalloys by zirconium addition |
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